Recently, three-dimensional (3D) structure reconstruction, virtual reality (VR), 3D printers, and 3D display technology are being actively developed. Such technologies are based on accurately obtaining depth information, and to this end, various pieces of equipment have been developed and released in the market.
However, in a case of obtaining depth information from various depth sensors or image information, in terms of a corresponding color image, a resolution is low, or there is much noise generally.
If the quality of the depth information is not good, results of various technologies using the depth information are adversely affected, and thus, an operation of removing noise from an initially obtained depth map having a low resolution and low quality is needed.
Moreover, since the depth information has characteristic where a depth continuation region and a depth discontinuation region are relatively clearly differentiated from each other, an operation of removing noise needs consideration of the depth information.
In this context, Korean Patent Registration No. 10-1526866 (title of invention: apparatus and method of filtering out depth noise by using depth information) discloses details for performing spatially filtering or temporally filtering according to depth information.